/Engine/Source/Runtime/Engine/Classes/PhysicalMaterials/PhysicalMaterialMask.h
Helper method to query phys mat index at a given UV position in mask data.
static uint32 GetPhysMatIndex ( const [TArray](API\Runtime\Core\Containers\TArray)< uint32 > & MaskData, int32 SizeX, int32 SizeY, int32 AddressX, int32 AddressY, float U, float V )